800cc ONLY! We have pondered the feasibility of “un-linking” the drivetrain on the 800cc ProClimb since its introduction in 2012. So here is what we have been working on...obviously these are not polished poster boy shots but down and dirty photos of real test parts on my sled that show exactly what it is, how it fits, and how it works. Introducing the SKookum Un-linkeD (SKUD) Motor Plate 2012-2014 Proclimb 800cc
Figure 1: SKUD Motor Plate, Locked-in-Socket multi-directional bump stop, and solid mounted jackshaft with carbon fiber brackets.
The main design challenges have been:
1. The structural integrity of the bulkhead and its ability to support a solid mounted jackshaft without major chassis modification. We were able to engineer a lightweight yet simple bracket system that is 100% bolt on and adequately reinforces plus spreads new loads to the bulkhead. The release of the Yamaha Viper this past spring also seems to be a good indication that other very smart people also think it is ok from a structural concern to solid mount the jackshaft in the ProClimb
2. The 800cc motor is subject to what we consider to be excessive movement, even in stock form with a TCL. In our opinion, the stock motor mounts cannot support additional loads from an un-linked drivetrain. The TTCF and our existing tooling was the perfect platform from which to launch our 800cc specific motor plate that addresses this issue.
So it was time to unring the bell and unlearn everything we have come to understand about the TCL. First it is not all peaches and cream with a solid mounted secondary and motor supported on rubber mounts! How about the M series with frequently torn mounts in the motor plate, cracked bulkheads from trying solid or stiffer mounts, adding extra torque stops here and there, extra mag side mounts, TM1000s that ate belts, and blown Diamond Drives to boot! So we would not assume that an un-linked drivetrain in the ProClimb would work any better, especially since the TTCF already addresses what we still see as the main issue with excessive motor movement and mis-aligning clutches under load. So there was no point in us pursuing this unless we could engineer a superior set up that also addresses the last remaining issue we see with a solid link between the clutches…. finicky set up and it is very sensitive.
The three main components are:
1: Triangulated motor plate: The SKUD motor plate has three mount locations that attach to the main lower frame rail, shock tower, and bulkhead. New loads placed on the motor plate from un-linking the drivetrain are evenly distributed amongst the strongest points on the chassis in a triangulated arrangement to best prevent the motor from moving as the clutches are pulled together. We were 80% of the way there with the TTCF so I just chopped the neck off a scrap piece, opened up the hole where the IABS was for a third mount, and done!
2. Locked-in-Socket multi-directional bump stop: Our semi-circle shaped rubber bump stop shown in Figure 1 resists motor plate movement over 160° range of motion and effectively cancels out some of the forces between the motor plate and jackshaft mount.
3. Solid mounted Jackshaft: We have retained the use of the stock bearing hub and designed inboard and outboard bearing support brackets along with a light weight spacer that solid mounts the jackshaft to multiple locations on the bulkhead. This set up spreads the load to different points and sides on the bulkhead and provides a wide range of support lengthwise along the jshaft. Using all stock bolt hole locations per usual Skookum style:whoo: Please note that although there are major benefits to using a normal bearing with this set up, you do NOT have to remove the jackshaft and replace the bearing (major PITA) and can simply bolt on the brackets.
Figure 2: In-board Carbon Fiber Jack Shaft Bracket.
Figure 3: In-board Bracket installed on the inside of the bulkhead.
Figure 4: Spacer between the bearing hub and inboard bracket with carbon fiber outboard jackshaft bracket. (This is a proto-type, production part is highly machined lightweight honeycomb design).
So what does it all mean lol?! In the end we have seven (7) mount locations that we feel supports the Suzuki motor better than anything we have seen yet. The main advantages of the SKUD Motor Plate are:
1. Clutch Alignment: We have gone back to an alignment specification very similar to the M Series. Without a rigid torque link the primary and secondary are pulled together and this “give” allows the clutches to come into alignment. The TCL may do a better job of maintaining center to center but can compromise alignment due to motor movement forcing the jackshaft to come out of vertical and horizontal parallelism. Self-aligning bearings can also allow the jackshaft to flex/bow adding to the problem.
On a fundamental level, keeping the clutches in alignment seems more important than maintaining center to center for good belt life and lowered temperatures! When you have both with the TTCF I still maintain that this is one of the most efficient drivetrains to ever hit the snow but set up is key…
2. Finicky Set Up: If the clutches are solid mounted they need to be held to a tighter alignment specification. There are inherent variations in how these motors sit in the chassis, which also influences where the jackshaft is located. Then there are variations in how far the jackshaft is seated in the tapered bore of the chain case bearing... All of these must be dialed in for the best performance. Most of the ProClimbs are close enough but we have seen a big spread on stock sleds.
We also feel that the rigid link set up may be more sensitive to flaws in the clutches, and vice versa. As in when there is no give between the clutches, they may be more prone to binding from uneven or shock loads, and machining imperfections in the sheaves may have more of an affect. Also if the clutches are forced out of alignment by the TCL as the motor moves it may promote binding and other issues. Again, good clutches and proper set up you should be good to go…but this is just not how it has been working out on a lot of these sleds from the factory.
3. Chain Case Durability: There have been more long term durability issues with the chain case surfacing now that these sleds have more miles. The “wondering” jackshaft with the stock TCL set up and resulting angular misalignment of the upper gear in the chain case can cause premature wear and failure of the chain, as well as the auto tensioner. These issues are eliminated with a solid mounted jackshaft (not that any chain case is invincible but you get the idea). Should work great with the C3 Belt Drive!
So despite a very disappointing snow year here in the PacNW I managed to finish preliminary testing and a first production run of these parts. So far the results have been very impressive but I still plan on giving out five (5) free R&D parts to a variety of riders (that hopefully have more snow than we do) and letting them report back. As soon as I contact these folks individually to make sure they are still on board I will introduce them here. Stay tuned.
Thanks, Ryan
Figure 1: SKUD Motor Plate, Locked-in-Socket multi-directional bump stop, and solid mounted jackshaft with carbon fiber brackets.
The main design challenges have been:
1. The structural integrity of the bulkhead and its ability to support a solid mounted jackshaft without major chassis modification. We were able to engineer a lightweight yet simple bracket system that is 100% bolt on and adequately reinforces plus spreads new loads to the bulkhead. The release of the Yamaha Viper this past spring also seems to be a good indication that other very smart people also think it is ok from a structural concern to solid mount the jackshaft in the ProClimb
2. The 800cc motor is subject to what we consider to be excessive movement, even in stock form with a TCL. In our opinion, the stock motor mounts cannot support additional loads from an un-linked drivetrain. The TTCF and our existing tooling was the perfect platform from which to launch our 800cc specific motor plate that addresses this issue.
So it was time to unring the bell and unlearn everything we have come to understand about the TCL. First it is not all peaches and cream with a solid mounted secondary and motor supported on rubber mounts! How about the M series with frequently torn mounts in the motor plate, cracked bulkheads from trying solid or stiffer mounts, adding extra torque stops here and there, extra mag side mounts, TM1000s that ate belts, and blown Diamond Drives to boot! So we would not assume that an un-linked drivetrain in the ProClimb would work any better, especially since the TTCF already addresses what we still see as the main issue with excessive motor movement and mis-aligning clutches under load. So there was no point in us pursuing this unless we could engineer a superior set up that also addresses the last remaining issue we see with a solid link between the clutches…. finicky set up and it is very sensitive.
The three main components are:
1: Triangulated motor plate: The SKUD motor plate has three mount locations that attach to the main lower frame rail, shock tower, and bulkhead. New loads placed on the motor plate from un-linking the drivetrain are evenly distributed amongst the strongest points on the chassis in a triangulated arrangement to best prevent the motor from moving as the clutches are pulled together. We were 80% of the way there with the TTCF so I just chopped the neck off a scrap piece, opened up the hole where the IABS was for a third mount, and done!
2. Locked-in-Socket multi-directional bump stop: Our semi-circle shaped rubber bump stop shown in Figure 1 resists motor plate movement over 160° range of motion and effectively cancels out some of the forces between the motor plate and jackshaft mount.
3. Solid mounted Jackshaft: We have retained the use of the stock bearing hub and designed inboard and outboard bearing support brackets along with a light weight spacer that solid mounts the jackshaft to multiple locations on the bulkhead. This set up spreads the load to different points and sides on the bulkhead and provides a wide range of support lengthwise along the jshaft. Using all stock bolt hole locations per usual Skookum style:whoo: Please note that although there are major benefits to using a normal bearing with this set up, you do NOT have to remove the jackshaft and replace the bearing (major PITA) and can simply bolt on the brackets.
Figure 2: In-board Carbon Fiber Jack Shaft Bracket.
Figure 3: In-board Bracket installed on the inside of the bulkhead.
Figure 4: Spacer between the bearing hub and inboard bracket with carbon fiber outboard jackshaft bracket. (This is a proto-type, production part is highly machined lightweight honeycomb design).
So what does it all mean lol?! In the end we have seven (7) mount locations that we feel supports the Suzuki motor better than anything we have seen yet. The main advantages of the SKUD Motor Plate are:
1. Clutch Alignment: We have gone back to an alignment specification very similar to the M Series. Without a rigid torque link the primary and secondary are pulled together and this “give” allows the clutches to come into alignment. The TCL may do a better job of maintaining center to center but can compromise alignment due to motor movement forcing the jackshaft to come out of vertical and horizontal parallelism. Self-aligning bearings can also allow the jackshaft to flex/bow adding to the problem.
On a fundamental level, keeping the clutches in alignment seems more important than maintaining center to center for good belt life and lowered temperatures! When you have both with the TTCF I still maintain that this is one of the most efficient drivetrains to ever hit the snow but set up is key…
2. Finicky Set Up: If the clutches are solid mounted they need to be held to a tighter alignment specification. There are inherent variations in how these motors sit in the chassis, which also influences where the jackshaft is located. Then there are variations in how far the jackshaft is seated in the tapered bore of the chain case bearing... All of these must be dialed in for the best performance. Most of the ProClimbs are close enough but we have seen a big spread on stock sleds.
We also feel that the rigid link set up may be more sensitive to flaws in the clutches, and vice versa. As in when there is no give between the clutches, they may be more prone to binding from uneven or shock loads, and machining imperfections in the sheaves may have more of an affect. Also if the clutches are forced out of alignment by the TCL as the motor moves it may promote binding and other issues. Again, good clutches and proper set up you should be good to go…but this is just not how it has been working out on a lot of these sleds from the factory.
3. Chain Case Durability: There have been more long term durability issues with the chain case surfacing now that these sleds have more miles. The “wondering” jackshaft with the stock TCL set up and resulting angular misalignment of the upper gear in the chain case can cause premature wear and failure of the chain, as well as the auto tensioner. These issues are eliminated with a solid mounted jackshaft (not that any chain case is invincible but you get the idea). Should work great with the C3 Belt Drive!
So despite a very disappointing snow year here in the PacNW I managed to finish preliminary testing and a first production run of these parts. So far the results have been very impressive but I still plan on giving out five (5) free R&D parts to a variety of riders (that hopefully have more snow than we do) and letting them report back. As soon as I contact these folks individually to make sure they are still on board I will introduce them here. Stay tuned.
Thanks, Ryan
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